Hydrophobia helps UGA researcher attack pollutants

They’re everywhere, and they’re proving to be nearly indestructible — and humans made them.

Perfluorocarbon chemicals are used in everything from carpet manufacturing to firefighting, but the problem is once they’re released into the environment, they’re hard to get rid of.

Qingguo “Jack” Huang is an assistant professor of crop and soil sciences at the University’s Griffin campus. The U.S. Department of Defense has given him almost $700,000 to continue his research on a potential method for breaking down PFCs in the environment.

The reason PFCs are so hard to degrade is the strength of the bonds that hold the molecules together.

“These chemicals were designed by chemists to be robust,” Huang said. “They basically replaced all hydrogen atoms in the molecule with fluorine. That makes the chemical bond super strong and hard to break.”

The traditional method of trying to break carbon-fluorine bonds is by producing free hydroxyl radicals, which are highly reactive and attack bonds. Huang said the problem with this method is PFCs are afraid of water.

“The traditional oxidation process doesn’t work because these molecules are extremely hydrophobic,” he said. “The free radicals you are generating in the traditional ways — they like water. That’s why they don’t go together. That’s why they don’t tend to attack these molecules. We’re trying to design a new process.”

Huang has had laboratory success breaking down PFC bonds but is unsure why his method has worked, he said. He believes it is because his enzymatic approach creates hydrophobic free radicals, which can more easily attack hydrophobic PFCs.

Huang said the grant will help him “to understand better and also fully optimize the process, to make it work under real conditions.”

Because the chemicals don’t degrade easily, Huang said, there are many more of them staying in the environment — potentially getting into groundwater.

“Analytical capabilities have been developed so much over the years, so now we’re able to detect even when concentrations are so low,” Huang said. “That allows us to find that these chemicals are everywhere.”

The Environmental Protection Agency is in the process of determining if it will move to regulate PFCs. While no evidence has been shown that humans are significantly affected through exposure to these chemicals, they have proven toxic to animals in laboratory settings.

“I guess the biggest thing for me is: why do they use it?” asked Laura Eckhardt, a third-year dietetics and music performance major from Peachtree City. “The fact that I don’t know if there are any alternatives or any better alternatives, then I would be hesitant to just have it completely shut down.”

PFCs are used in making items both fire-resistant and friction-resistant — perfect for non-stick frying pans and firefighting foams.

Huang said there are some alternative chemicals, and there are some companies who are beginning to use them voluntarily even though the EPA has placed no restrictions.

“Definitely the environment is important,” said Karsten Holmquist, a first-year international business major from Stockholm. “Obviously you don’t want to go out and say if it’s hurting you, you want to keep it on the market.”

Huang said one of the potential reasons the EPA has not moved to regulate PFCs on a wide scale — there are some individual states that have placed restrictions — is that there is nothing available to tell companies to use as a cleanup method.

PFCs often get into groundwater because of exposure at firemen training facilities, but Huang said firefighters probably don’t suffer from it.

“They may be exposed to this chemical, but just for a short period of time,” he said. “The [bigger] concern is that they are in water, and they are everywhere. The concern is the consistent exposure over a long time, to either human[s] or wildlife.”